1. a JRL, CNRS-ST2I, AIST, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan;, Email: olivier.stasse@aist.go.jp
2. b Vrije Universiteit, B-1050 Brussels, Belgium
3. c INRIA, Rhone-Alpes, 38334 Grenoble, France
4. d Vrije Universiteit, B-1050 Brussels, Belgium
5. e JRL, CNRS-ST2I, AIST, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
6. f JRL, CNRS-ST2I, AIST, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan
7. g JRL, AIST-IS, AIST, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan